1. Field of the Invention
The present invention relates generally to an exposure apparatus and method and, more particularly, to an exposure apparatus and method used for manufacturing, e.g., a semiconductor device and a liquid crystal display substrate, and especially having a plurality of illumination optical systems.
2. Related Background Art
In recent years, a liquid crystal display substrate has been often employed as a display device for a personal computer, a TV, etc.. This liquid crystal display substrate is manufactured by effecting patterning of transparent thin-film electrodes in a desired shape on a glass substrate photolithography. Employed as a device for this lithography is a projection exposure apparatus for exposing original patterns formed on a mask onto photoresist layers on the glass substrate via projection optical systems.
Further, it has been recently demanded to increase an area of the liquid crystal display substrate. With this demand, it is desired that an exposure area of the projection exposure apparatus be enlarged.